The disclosure relates generally to distribution of communications signals in a distributed antenna system (DAS), and more particularly to an analog DAS supporting distribution of digital communications signals interfaced from a digital signal source and analog radio frequency (RF) communications signals.
Wireless customers are increasingly demanding digital data services, such as streaming video signals. Concurrently, some wireless customers use their wireless devices in areas that are poorly served by conventional cellular networks, such as inside certain buildings or areas where there is little cellular coverage. One response to the intersection of these two concerns has been the use of DASs. DASs can be particularly useful when deployed inside buildings or other indoor environments where client devices may not otherwise be able to effectively receive RF signals from a source. DASs include remote units configured to receive and transmit communications signals to client devices. The remote units can be provided as remote antenna units configured to wirelessly receive and transmit wireless communications signals in antenna range of the remote antenna units.
A typical DAS comprises head-end equipment (HEE) communicatively coupled to a plurality of remote units. The HEE connects to a variety of wireless services, such as wideband code division multiple access (WCDMA), long term evolution (LTE), and wireless local area network (WLAN) communications services. To distribute such wireless communications services in a DAS, the wireless communications services can be provided in the form of analog RF communications signals to the HEE of the DAS. Analog RF communications signals are RF communications signals that are modulated with carrier frequency and processed as analog signals in the DAS. In some cases, it may be desired for wireless communications services to be distributed as digital signals. In this regard, a digital DAS may be provided that contains distribution components configured to process digital communications signals in baseband for enhanced signal quality and processing. For example, digital signal processing and encoding schemes (e.g., I-Q modulation) can be employed for digital communications signals. Although digital DASs can have advantages over analog DASs, digital DASs can be more expensive than analog DASs due to the additional expense of digital signal processing components.
No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents.